热力耦合作用下地下盐岩储气库注采运行稳定性研究

Study on the injection-production stability of underground salt rock gas storage under thermo-mechanical coupling

彭井宏 周军 胡承强 黄薪宇 梁光川

西南石油大学石油与天然气工程学院，四川 成都 610500 中国石油西南油气田分公司安全环保与技术监督研究院，四川 成都 610500

在地下盐岩储气库注采运行过程中，因腔内气体压力和温度变化而产生的地层压力和热应力变化，会影响腔体围岩的稳定，从而影响整个储气库的稳定性。为探究热力耦合条件下地下盐岩储气库运行的稳定性，建立了储气库腔体温度和压力计算模型，对不同注采速率和注采时间的腔体温度和压力进行计算，将计算值作为数值模拟的边界条件，运用FLAC 3D软件模拟注采过程中的腔体稳定性变化情况。结果表明：如果只考虑压力的影响（压力作用），则腔体在注采过程中只发生剪切损伤；如果同时考虑压力和温度影响（热力耦合作用），则腔体在注气过程中会产生剪切损伤，在采气过程中会产生拉张损伤、剪切损伤和膨胀损伤。研究成果对地下盐岩储气库运行安全管理具有一定的指导意义。

During the injection?鄄production process in underground salt rock gas storage, the change of formation pressure and thermal stress caused by the gas pressure and temperature in the cavity will affect the stabilization of the surrounding rock, thereby affecting the stability of the cavity. In order to explore the operational stability of the salt rock gas storage under the thermal and mechanical coupling conditions, a calculation model for the cavity temperature and pressure in the salt rock gas storage was established. The model is used to calculate the cavity temperature and pressure under different injection?鄄production rates and injection?鄄production times, and the results are introduced into the FLAC 3D software as the boundary conditions of the numerical simulation to simulate the cavity stability changes during the injection?鄄production process. The research results show that under the action of pressure, only shear damage will occur in the cavity during the injection?鄄production process. However, under thermo?鄄mechanical coupling by dual function of pressure and tempreture, shear damage will occur in the cavity during the gas injection process, and tensile damage, shear damage and expansion damage shear damage will occur in the cavity during the gas production process. The research results have certain guiding significance for the operation and safety management of underground salt rock gas storage. 

10.6056/dkyqt202305019